Over the years, the dæmian community has coined quite a few terms ('dæmian' among them) regarding dæmons in order to more easily discuss their states and our interactions with them. Some are intuitive and others are not, so if you want to feel in the know before being bombarded by random slang, you might want to read over this handy lexicon composed by Gienah.

analysis
An interpretation of animal traits into human personality characteristics using standard interpretation guidelines determined by the dæmian community.

changeling
A settled dæmon whose form changes, possible because the dæmon's form is an act of imagination, not an objective state. This term is falling out of use since dæmons are now considered to be "mental constructs" rather than spiritual entities; even most settled dæmons change at least occasionally. The word is now most commonly applied to a dæmon that usually takes its settled form, and only has one or two other forms it becomes.

CIEday
Coming-Into-Existence Day. It is the specific date when your dæmon became known to you as your dæmon, in a personal way. (ie, not when you said, "Oh, I have a dæmon!" but when you said "My dæmon is a wolf named Lenira.") Also used to denote the anniversary of this event. Sometimes the exact date is unknown, and is approximated.

comfort form
A form that's taken for emotional reasons, to cheer someone up or make them feel stronger or braver, but isn't the settled form. Sometimes these are mistaken for settled forms, and can be hard to let go of. See also "surrogate form".

contrast analysis
A dæmon analysis that compares the characteristics of two similar forms.

crisis
A period of uncertainty about a previously certain dæmon form, name, or gender. Can also be preceded by one of those words: eg, "name crisis"; "gender crisis."

cross-form
A form that is a different sex from the dæmon's gender: eg, a female dæmon takes a peacock form, or a male dæmon takes a lioness form.

cross-settle
To settle as a cross-form.

dæmian
Someone who knows their dæmon and speaks with them on a regular basis.

dæmling
A little-used term for a dæmon that is newly discovered (i.e. the human hasn't known them long); can also be used to describe the new dæmian.

dæmon
A personified version of the second half of someone's mental dialogue, usually mentally represented in an animal form. Usually has a name, gender and personality; usually the dæmon's personality is at least somewhat different from that of the person. Comes from the Greek word "daimon", a minor spirit (either good or evil). Also "dæmon".

"Dæmon" is pronounced "demon" according to His Dark Materials, but some members prefer to pronounce it as "day-mon", to differentiate it from the infernal entity.

dæmonism
The practice of speaking to a dæmon.

dæmonology
An alternate word for "dæmonism," preferred by some due to its connotation of study and knowledge rather than religion.

daimon
Another word for "dæmon." Taken from the Greek spelling and sometimes used by members wishing to differentiate it from the word "demon." Also used as the spelling of "dæmon" in some translations of His Dark Materials.

false settling
The event of believing oneself to be settled but later realizing you were, for whatever reason, wrong. Either the form was wrong or the personality was still changing.

fluid
A synonym for "unsettled" which some members prefer because it removes the negative prefix and may be used by members who do not feel that the concept of settledom describes their dæmonic experience.

form
The shape your dæmon takes, generally an animal.

formism
Being irrationally biased against certain forms: either taking them yourself, or people who take those forms.

form possessiveness
Feeling like one "owns" a certain form and not wanting others to take it, or like one must "approve" people before they can use that form. Someone can be form-possessive about any form, not just their settled form: a form they took for a very long time, a form they love or have a pet of, or even just a form they know a lot about or wrote the analysis for.

formal name
A less-often used version of a dæmon's name, for formal situations. Often considered to be their 'full' name and sometimes known only to the dæmon and person.

hei, shei, wei
Can be used to differentiate between reference to your dæmon or someone else, your dæmon being referred to by the pronoun with the 'i'. (ie, "Hei's very funny" refers to your dæmon, while "He's very funny" refers to your friend Jonathan.) Falling out of common usage.

mate
Your dæmon's "partner": your partner's dæmon.

mental construct
The idea that dæmons are something that people "do" with their minds, rather than something that exists objectively and independently of us.

nameling
A dæmon who is nameless, or whose name keeps changing. Their true name has not been discovered yet. Not commonly used.

orthodox dæmian
Describes someone who holds a more traditional view of dæmons, such as they cannot settle as humans and the analysis of a settled form must reflect the person. Not commonly used.

OTF
"One true form." Refers to the same concept as "true form" or "settled form," but with stronger connotations of objectivity. It's often used to debate whether there is such a thing as a "true" form for everyone. Taken from the fandom expression "OTP" or "one true pairing," a romantic partnership considered to be the only possible one for the characters in question, which is in turn taken from the expression "one true god."

OTOF
"One true other form." The form that would be taken if the person were not his or her settled form, or the form he or she would take if his or her settled form were a different type (class, order, family, genus) of animals.

projection
The imagining of the dæmon interacting with the external environment.

QA
Quick analysis. An old term for a short analysis.

RA
See "reverse analysis".

reverse analysis
A description of someone's personality posted in the hopes that TDFers can thereby identify their dæmon form. So called because the original practice was to simply analyze whatever form someone's dæmon took; to find a form by looking at someone's personality was a reversal of this.

settle
To move into a fixed personality in late adolescence or adulthood, at which point it is possible to determine the dæmon's true form, or to decide on your dæmon's true form; to become sure and commit to a form as the final one. The two events don't always coincide, since your personality can settle before you've discovered the animal that will be your dæmon's true form.

settledom
The state of being settled.

settled-unknown
A dæmon of someone whose personality has settled, but who cannot find a form.

settler
An older term for "settled-unknown."

SFday
Short for "settled form" day. It's the day your dæmon settled: either the day you discovered what became their settled form, or, more commonly, the day you decided to "declare" settledom and announce it as your settled form.

the sig effect
The process by which a form can become associated with a person, and thereby their personality, because that person has had the form (especially in their signature) for so long. Causes problems when people compare people to other people, not the form itself.

-soul
A suffix used with an animal name to identify someone who has that animal as their form. For instance, "dog-soul," "bat-soul," "gecko-soul." Does not imply that the person's soul is literally that animal (which would make them an otherkin or therian) or even affirm the existence of souls.

stable
A person and/or dæmon who has a form that has been comfortable and fitting for a long time, but doesn't consider their personality settled. Compare "settling".

surrogate form
An alternate form that is taken for long periods of time by settled dæmons because the human is uncomfortable with the true form, or is simply used to the alternate form. See also "comfort form".

true form
The settled form of a dæmon. The form which best describes a person in their most true state.

uberwolf
Common forum slang for a dæmon that has clearly been 'pimped out' by a member who is attempting to make themselves more unique than they truly are. (Examples include wolves and big cats with unusual fur colouration, wings, and/or other extreme additions; mythical animals with special powers.)

unsettled
A dæmon that doesn't yet have a true form, or a person who hasn't reached a consistency of character sufficient to determine their true form. The dæmon may change frequently, or stay in a surrogate, stable, or comfort form.

unseparated
A term applied to someone who doesn't talk to their dæmon, or the hypothetical dæmon itself, especially if they previously were a dæmian.

viable form
Because dæmons are projected as an act of imagination, they can take whatever shape you wish; however, the community believes that only certain forms are "viable" as settled forms. This includes most organisms in the kingdom Animalia. Forms generally agreed not to be viable are humans, impossible hybrid forms, non-animal forms, inanimate forms, and forms that are completely made up. Mythic forms are usually, but not always, not considered viable. Theoretically, forms like worms and slugs are viable, but it's unlikely they'd ever completely describe a person. There are strong minorities who do not consider primates, extinct forms, or man-made hybrid forms viable. Each of these have varying levels of support in the community (primates likely the most, and man-made hybrids likely the least) but they are the most contentious.

vibe
A vague and undefinable sense of what a certain form's personality is like. Eg, "I get snake vibes from you."